Scientific Forecaster Discussion
fxus65 kslc 231634
Area forecast discussion
National Weather Service Salt Lake City Utah
1034 am MDT Wed Aug 23 2017
Synopsis...an upper level trough moving north through northern
Utah will exit the state this morning. A gradual warming and
drying trend will take hold across the region as high pressure
aloft returns to the Great Basin later in the week.
Discussion...shortwave energy continues to move across the
forecast area this morning. The largest of the shortwaves in the
near term is moving out of northern Utah at this time, but a few
showers continues near the Utah/Idaho border as well as over southwest
Wyoming. These will tend to weaken by the afternoon. Skies are
mostly clear over central and southern Utah in a more subsident
airmass in the wake of this feature. However, additional
shortwaves are on track to move through southern Utah this
afternoon, combining with daytime heating to destabilize the
airmass. Updated the forecast earlier to raise pops slightly this
afternoon, primarily for southern Utah.
Behind the exiting shortwaves tonight, the forecast area should
see a gradual drying and warming trend beginning Thursday as high
pressure builds over the region. Lingering moisture and
instability should allow for a few showers and thunderstorms over
the higher terrain, at least through the work week, but there will
be a noticeable downward trend in the coverage of afternoon and
evening convection. By early next week, maxes are expected to run
at least a few degrees above seasonal normals.
No additional updates planned this morning.
Aviation...the slc terminal will see VFR conditions throughout
the day with generally decreasing high and mid level clouds.
Southeast winds are expected to shift to the northwest between 19z
and 20z, but there is a 20 percent chance that nearby showers will
result in periods of gusty and/or erratic winds at the terminal
this afternoon and this evening.
Fire weather...a shortwave that is producing a few showers and
thunderstorms primarily near the Utah/Idaho border will exit the
district this morning. Additional instability will allow for
primarily isolated coverage of showers and thunderstorms across
the area this afternoon into early this evening.
A general drying trend will begin from the south by tonight, and
continue over the next several days as high pressure aloft slowly
strengthens across the Great Basin. Enough lingering moisture
will remain across the state to support afternoon/evening terrain-
based convection the next several days. The areal coverage of
this convection will be limited with little chance at wetting
rains. Temperatures will also climb a bit, with readings running
at or above normal across all fire districts well into the
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